Dual firmness spring for bedding and the like



March 4, 1969 M. N.JANAPOL 3,

DUAL FIRMNESS SPRING FOR BEDDING AND THE LIKE Filed March 30, 1967 INVENTOR.

. M'LV/A M JIM/11 04 BY United States Patent 4 Claims ABSTRACT OF THE DISCLOSURE This invention relates to furniture springs and the like and particularly to bedding springs that are employed for the support of a layer of padding adapted to engage and comfortably carry the body weight of a person resting thereon. The posture of the resting person can vary widely and when the person reclines a bed or mattress is used and which is made up a multiplicity of spring coils, each of which is the subject of this invention, it being a general objecto to provide an improved spring coil having dual firmness; an initial softness and a subsequent hardness. In accordance with this invention the softness and hardness are incorporated in the single spring coil, presenting a pillow-like surface without resort to soft padding alone and presenting an underlying firmness despite the softer surface action.

Bedding mattresses are characteristically of some specified firmness and are also constructed in various manners so as to alter the firmness thereof in certain areas. Heretofore, the required variations in firmness have been achieved by installing springs of differing compression capabilities. That is, springs of different gage wire have been used, the design of said springs remaining substantially the same. In fact, the hour-glass shaped spring is universally employed, the commercial production of such springs being highly developed to the point where all of these springs are substantially alike, being automatically produced by spring coiling machines. Consequently, the usual spring of the type under consideration has three full and continuously varying convolutions embodied in two opposed conical sections with their enlarged and opposite base ends closed into load carrying and supporting rings respectively.

The ordinary spring of the type under consideration is almost invariably constructed as above specified for the purpose of affording a progressive and silent action in the support and/0r carrying power gained as a function of compressive action. Since the endmost convolutions of larger diameter are more easily deflected than the innermost convolutions of smaller diameter, there is an infinitely variable increase in resistance as compression occurs. However, this accepted prior art development employs a continuously varying helix radius whereby the springs are of curvilinear hour-glass shape, and to the end that the endmost convolutions progressively engage and bottom out against the support and the person carrying padding. As a result, the common bed springs flatten with a substantially uniform increase in support and carrying power, the convolutions of the springs progressively coming into engagement with the support and padding respectively. Consequently therefore the ordinary springs of this type are necessarily of some specified firmness, either hard, medium or soft as circumstances require.

An object of this invention is to improve upon the springs of the type hereinabove specified and to provide at least two distinct supporting and/or carrying pressures whereby the desirability of both softness and firm- 3,430,275 Patented Mar. 4, 1969 ness is realized. It is widely accepted that softness in a mattress is to be desired but at the expense of firmness for proper body support, and to the end that persons with orthopedic problems resort to mattresses of greater firmness. Thus, the comfort of a soft mattress is sacrificed for the required firmness, and vice versa. In other words, combined softness and firmness has been unobtainable, and in a firm mattress of the prior art only the padding contributes to softness for comfort.

Another object of this invention is to provide a dual capacity bed spring of the character referred to and which is fundamentally of firm supporting capacity and which is also of softer carrying capacity for the persons comfort respectively. The spring per se of the present invention is sectional and as such has a section for firmness and a section for softness. The two spring sections are successively operable, the section for softness being initially operable to receive the body contact of the person and the gently applied pressures, while the section for firmness is operable only upon the increased application of body supporting pressures.

It is still another object of this invention to successfully employ a coil spring of cylinder form, having a uniform helix diameter, as a bedding spring. With the spring as it is disclosed herein there is a section of cylindrical form which continues integrally and uninterruptedly into a section of conical form. The helix radii of the conically formed section gradually increases to large diameter for softness as a body carrier, while the diameter of the cylinder form remains constantly reduced for firmness as a. body support.

The various objects and features of this invention will be fully understood from the following detailed description of the typical preferred form and application thereof, throughout Which description reference is made to the accompanying drawings in which:

FIG. 1 is a sectional view of a portion of a typical mattress construction, undepressed, and shows the application of the spring coils of the present invention. FIG. 2 is a view similar to FIG. 1 and shows depression of the carrier section of the spring coils, the support section remaining substantially undepressed for firmness. FIG. 3 is a side elevation of one of said springs coils and FIG. 4 is an end view of the same.

Coil springs for use in mattresses and like furniture are characteristically hour-glass shaped for predetermined purposes facilitating assembly of the products made thereof and for predetermined operational functions. For example, it is desirable to have maximum engagement diameter at opposite ends of the spring coils for support and carrying capacity, and it is also desirable that the intermediate coils be small in diameter so as to avoid interference with each other.

A typical bedding unit, for example a mattress, involves a multiplicity of spring coils X, opposite padding Y and ticking Z in the form of an envelope enclosing the entire mattress as a unit. In the drawings I have shown a fragmentary portion of a mattress involving the three specified elements X, Y and Z, the spring coils X providing the carrying and support capacities, and the cover Z providing for the protection of padding Y. The specific construction, of furniture, can vary widely in utilizing the dual purpose spring coils X hereinafter described.

The spring coil X embodies the same general features of construction that are found in the prior art coils of the special type under consideration, and this is particularly advantageous in that existing spring coiling machines are readily adapted to the manufacture of this new and improved spring coil X. However, there are distinguishing features in the present spring coil X which require modification in the spring coiling machines, for the purpose of establishing distinct sections each with its separate functions. Accordingly, the spring coil X involves generally, a support section A and at least one carrier section B. The support section A serves as the firmness foundation while the carrier section B serves as the soft barrier for body engagement, and in practice the mattress is two sided in which case the spring coil X has sections B at opposite ends. The details of joining adjacent spring coils is well known in the art and forms no part of the present invention.

The spring coil X is formed of a single length of spring wire 10 turned into a helical configuration of hour-glass shape the opposite ends 12 and 13 of the spring are closed and the terminal ends of the wire are secured by wrapping 14 at each opposite end convolution, forming a fiat 360 ring for hearing engagement upon and against the supporting padding and body carrying padding respectively. For example, said securement at 14 is gained by wrapping or winding of the wire onto itself, as clearly shown in the drawings. The closed ends 12 and 13 are in spaced parallel planes and are of susbtantially true diameter forms normal to and concentric with the coil spring axis a.

In accordance with the invention the support section A serves as the firm foundation of the spring, so that bottoming out thereof will not occur under normally expected loading. Support section A is of cylinder form having a uniform helix diameter and of designed proportions to give the desired yieldable firmness of support. That is, a spring wire gage is employed which establishes the desired resistance to depression when combined with the employment of a certain spring diameter and helical pitch. In other words, these known spring factors are balanced relative to each other according to the science of this art, in order to have a straight cylindrical spring support section A of substantially constant spring rate. In practice, the support section A is at least and preferably more than one full turn, and is shown for example as two full turns.

A feature of the present invention is the comparatively small diameter of the support section A, whereby the resultant stiffness and consequent firmness of this section is quite high. That is, the constant helix diameter of section A is small in comparison to the diameter of the closed ends 12 and 13, and the cylindrical spring form is quite firm and affords substantial and constant resistance to depression.

In accordance with the invention the carrier section B serves as the soft barrier for body engagement of a person resting upon or reclining upon the spring coil X (or set of springs). The carrier section B is of conical form having an ever widening helix radius as it continues from the section A to the spring end 12 or 13. The ever increased helix radius of section B renders the spring coil X less resistive to depression as the ends 12 and 13 are reached. And as a consequence, the end extremities of spring coil X are first deflected, followed by a progressive deflection of the innermost coils. In practice, the section B is a full turn and extend between the cylindrical support section A and end 12 or 13 in an ever widening form.

A feature of the present invention is the comparatively large ultimate radius of the carrier section B, whereby the resultant softness is greatest at or near each end 12 and/or 13, the resistance against depression gradually increasing toward the support section A. As in the case of conical springs, the convolutions of the section B progressively bottom out against the padding Y with initial softness and ever increasing resistance; until the endmost convolution of the support section A commences to bottom out, whereupon the spring rate becomes substantially constant and the desired degree of firmness is maintained.

From the foregoing it will be seen that the spring coil X has retained all of the beneficial features of the prior art bedding springs, but with a separation of the two opposed conical carrier sections B. Accordingly, the support section A is inserted beneath the section B, or between the two sections B, and due to its form has entirely different spring rate properties than said conical sections. In carrying out the invention, the support section A is to be substantially stiffer and less yielding than the carrier section B, and a most practical way to accomplish this without change in wire gage is to reduce the helix diameter. A substantially constant and firm spring rate is then established in the straight cylinder portion of the spring coil, While a graduated soft-to-firm spring rate remains in the conical portion of the spring coil. The diminishing helix of the carrier section B gradually bottoms out so as to increase firmness from minimum to maximum, and said maximum firmness is then continuously exerted throughout the continued depression of the support section A having the constant spring rate characteristic. In practicing this invention, substantially heavier wire gages have been employed in constructing the spring coils X for the purpose of establishing the desired firmness, and this is made possible by the inclusion of a sufficient number of convolutions in the support section A, for example the two complete turns. Further, the initial softness is gained by the generous radius of the endmost portions of the carrier sections B as they first engage and bottom out against the padding Y.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any modifications of variations that may appear to those skilled in the art.

I claim:

1. A spring coil for the firm support of and initially soft depression of the padding of bedding and the like and formed of a length of spring wire, and including:

a conical carrier section formed of said wire and having a substantially complete turn of convolutions of progressively increased radius outwardly toward the padding engaging end of the spring coil,

and a straight cylindrical support section formed of said wire and having more than one complete turn of convolutions of constant diameter continuing inwardly from the decreased radius of the first mentioned section,

the spring rate of the first mentioned carrier section being initially soft and increased by the progressive engagement of the decreased radius of its convolutions, and the spring rate of the second mentioned support section being substantially constant and firm after depression of said first mentioned carrier section and upon subsequent depression of said support section.

2. The spring coil for bedding and the like, as set forth in claim 1 and wherein the support section convolutions include two complete turns as a straight cylindrical support section.

3. A double-ended spring coil for the firm support of and initially soft depression of the opposite paddin'gs of bedding and the like and formed of a length of spring wire, and including:

apposed and spaced conical carrier sections formed of said wire and each having a substantially complete turn of convolutions of progressively increased radius outwardly toward the opposite padding engaging ends of the spring coil,

and a straight cylindrical support section intermediate the first mentioned spaced carrier sections and formed of said wire and having more than one complete turn of convolutions of constant diameter continuing inwardly from the decreased radii of the first mentioned spaced carrier sections,

the spring rates of the first mentioned carrier sections being initially soft and increased by the progressive 5 6 engagement of the decreased radii of their convolu- References Cited tions, and the spring rate of the second mentioned UNITED STATES PATENTS and intermediate support section being substantially constant and firm after depression of said first men- 2260627 10/1941 Krakauer 5-256 X 2,626,408 1/1953 Wesley 5-351 tloned carrier SCL1OI1S against said padding and upon 5 3 190 631 6/1965 Kaiser X subsequent depression of said support section. 4. The double-ended spring coil for bedding and the CASMIR NUNBERG, Primary Examiner. like, as set forth in claim 3 and wherein the support section convolutions include a straight cylindrical sup- U.S. Cl. X.R. port section. 10 5256 

